Gustometry of diabetes mellitus patients and obese patients

The sensation of adequate taste detection can be associated with satisfaction of food intake. The impairment of taste detection may be associated with the development of obesity. Taste detection is determined hereditarily, but it can be influenced also by the occurrence of neuropathy. To find an explanation for these phenomena, we investigated 73 patients with diabetes mellitus (DM) 2 (i.e., non-insulin-dependent DM); 11 patients with DM 1 (i.e., insulin-dependent DM); 12 obese patients (body-mass index >30) without DM; and 29 control patients. All subjects underwent electrogustometric examination with Hortmman's electrogustometer. During this examination, we obtained electrical thresholds of taste by stimulating appropriate parts of the tongue. We stimulated the apex, middle, and near tongue radix areas on both sides. The resulting value is the average on the left and right sides of the mentioned areas. We considered a value of less than 40 microA to be normal. Values in excess of 100 microA are considered as hypogeusia. Values between 40 and 100 microA are taken as borderline, and ageusia is in excess of 500 microA. According to these criteria, in the DM 2 group, we found 40% of patients with hypogeusia, whereas in the DM 1 group, we found 33% of patients; 25% of patients were in the obese group. Among normal subjects (people without obesity or DM), no hypogeusia was found. We found ageusia in 5% of patients with DM 2, in 3% of patients with DM 1, and in 14% of obese patients. Among normal subjects, we found no ageusia. These results support the hypothesis that diminished taste detection can evoke hyperphagia and later obesity.